Optical lens

Abstract

The invention provides an optical lens, which comprises five lenses with focal power and sequentially comprises a first lens with negative focal power, a second lens with positive focal power, a third lens with negative focal power, a fourth lens with negative focal power, a fifth lens with negative focal power and a sixth lens with negative focal power from an object side to an imaging surface along an optical axis, the object side surface of the second lens is a convex surface, and the image side surface of the second lens is a concave surface; the third lens has negative focal power, and the image side surface of the third lens is a concave surface; the object side surface of the fourth lens is a convex surface, and the image side surface of the fourth lens is a concave surface; the fifth lens has positive focal power, and the object side surface of the fifth lens is a convex surface; wherein the focal length f2 of the second lens and the effective focal length f of the optical lens meet the following conditions: 0.8 lt; f2 / flt; 1.1. According to the optical lens provided by the invention, through specific surface shape matching and reasonable focal power distribution, the lens has one or more advantages of large image surface, long focus, large aperture, high imaging quality and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of imaging lenses, and particularly to an optical lens. Background Art

[0002] With the continuous improvement of people's requirements for driving experience, in-vehicle application optical lenses are increasingly used in intelligent driving, and the status of in-vehicle optical lenses in the automotive-related industry is constantly rising.

[0003] Advanced Driver Assistance Systems (ADAS) play an important role in intelligent driving. It collects environmental information through various lenses and sensors to ensure the driving safety of drivers. In addition to requiring the optical lens to have a thin, light, short and small shape and high pixel and high resolution characteristics, the existing ADAS system lenses also require the optical lens to be able to clearly image under low illuminance conditions. Therefore, an optical lens with good imaging effect needs to be developed. Summary of the Invention

[0004] In view of the above problems, the purpose of the present invention is to provide an optical lens with excellent imaging quality.

[0005] The technical solution adopted by the present invention is as follows: An optical lens, the number of lenses with optical power is five, and successively includes from the object side to the imaging surface along the optical axis: A first lens with negative optical power, the object side surface of which is concave; A second lens with positive optical power, the object side surface of which is convex and the image side surface of which is concave; A third lens with negative optical power, the image side surface of which is concave; A fourth lens with positive optical power, the object side surface of which is convex and the image side surface of which is concave; A fifth lens with positive optical power, the object side surface of which is convex; Wherein, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 0.8 < f2 / f < 1.1; the object side surface curvature radius R3 of the second lens and the effective focal length f of the optical lens satisfy: 0.6 < R3 / f < 0.95; the image side surface curvature radius R4 of the second lens and the effective focal length f of the optical lens satisfy: 5.5 < R4 / f < 8.5.

[0006] Further preferably, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: 0.65 < f12 / f < 1.3.

[0007] Further preferably, the clear aperture radius d1 of the object side surface of the first lens and the clear aperture radius d10 of the image side surface of the fifth lens satisfy: 1.3 < d1 / d10 < 2.1.

[0008] More preferably, the sagittal height SAG10 of the image side clear aperture of the fifth lens and the clear aperture diameter d10 of the image side clear aperture of the fifth lens satisfy: -0.1 < SAG10 / d10 < 0.1.

[0009] More preferably, the distance CT12 between the first lens and the second lens on the optical axis and the total optical length TTL of the optical lens satisfy: 0.22 < CT12 / TTL < 0.38; the distances CT23 between the second lens and the third lens on the optical axis, CT34 between the third lens and the fourth lens on the optical axis, and CT45 between the fourth lens and the fifth lens on the optical axis and the total optical length TTL of the optical lens satisfy: 0.025 < (CT23 + CT34 + CT45) / TTL < 0.04.

[0010] More preferably, the sagittal height SAG3 of the object side clear aperture of the second lens, the sagittal height SAG4 of the image side clear aperture of the second lens and the central thickness CT2 of the second lens satisfy: -0.5 < (SAG4 - SAG3) / CT2 < -0.27.

[0011] More preferably, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.8 < TTL / f < 4.

[0012] More preferably, the clear aperture diameter d1 of the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.8 < d1 / IH / tan(FOV / 2) < 1.1.

[0013] More preferably, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < f5 / f < 1.8.

[0014] More preferably, the central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy: 2.5 < CT2 / CT3 < 5.

[0015] The optical lens provided by the present invention uses five lenses with specific optical powers. Through specific surface shape combinations and reasonable optical power distributions, it can improve the imaging quality of the optical lens, reduce aberration, improve the imaging quality of the optical lens, and endow the lens with one or more advantages such as a large image plane, long focal length, large aperture, and high imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 This is a schematic diagram of the optical lens structure in Embodiment 1 of the present invention.

[0017] Figure 2 This is a field curvature curve diagram of the optical lens in Embodiment 1 of the present invention.

[0018] Figure 3 This is the F-Theta distortion curve of the optical lens in Embodiment 1 of the present invention.

[0019] Figure 4 This is an axial aberration curve of the optical lens in Embodiment 1 of the present invention.

[0020] Figure 5 This is a chromatic aberration curve of the optical lens in Embodiment 1 of the present invention.

[0021] Figure 6 This is a relative illumination curve of the optical lens in Embodiment 1 of the present invention.

[0022] Figure 7 This is a schematic diagram of the optical lens structure in Embodiment 2 of the present invention.

[0023] Figure 8 This is a field curvature curve diagram of the optical lens in Embodiment 2 of the present invention.

[0024] Figure 9 This is the F-Theta distortion curve of the optical lens in Embodiment 2 of the present invention.

[0025] Figure 10 This is an axial aberration curve of the optical lens in Embodiment 2 of the present invention.

[0026] Figure 11 This is a chromatic aberration curve of the optical lens in Embodiment 2 of the present invention.

[0027] Figure 12 This is a relative illumination curve of the optical lens in Embodiment 2 of the present invention.

[0028] Figure 13 This is a schematic diagram of the optical lens in Embodiment 3 of the present invention.

[0029] Figure 14 This is a field curvature curve diagram of the optical lens in Embodiment 3 of the present invention.

[0030] Figure 15 This is the F-Theta distortion curve of the optical lens in Embodiment 3 of the present invention.

[0031] Figure 16 This is an axial aberration curve of the optical lens in Embodiment 3 of the present invention.

[0032] Figure 17This is a chromatic aberration curve of the optical lens in Embodiment 3 of the present invention.

[0033] Figure 18 This is a relative illumination curve of the optical lens in Embodiment 3 of the present invention.

[0034] Figure 19 This is a schematic diagram of the optical lens structure in Embodiment 4 of the present invention.

[0035] Figure 20 This is a field curvature curve diagram of the optical lens in Embodiment 4 of the present invention.

[0036] Figure 21 This is the F-Theta distortion curve of the optical lens in Embodiment 4 of the present invention.

[0037] Figure 22 This is an axial aberration curve of the optical lens in Embodiment 4 of the present invention.

[0038] Figure 23 This is a chromatic aberration curve of the optical lens in Embodiment 4 of the present invention.

[0039] Figure 24 This is a relative illumination curve of the optical lens in Embodiment 4 of the present invention.

[0040] Figure 25 This is a schematic diagram of the optical lens structure in Embodiment 5 of the present invention.

[0041] Figure 26 This is a field curvature curve diagram of the optical lens in Embodiment 5 of the present invention.

[0042] Figure 27 This is the F-Theta distortion curve of the optical lens in Embodiment 5 of the present invention.

[0043] Figure 28 This is an axial aberration curve of the optical lens in Embodiment 5 of the present invention.

[0044] Figure 29 This is a chromatic aberration curve of the optical lens in Embodiment 5 of the present invention.

[0045] Figure 30 This is a relative illumination curve of the optical lens in Embodiment 5 of the present invention.

[0046] Figure 31 This is a schematic diagram of the optical lens in Embodiment 6 of the present invention.

[0047] Figure 32 This is a field curvature curve diagram of the optical lens in Embodiment 6 of the present invention.

[0048] Figure 33 This is the F-Theta distortion curve of the optical lens in Embodiment 6 of the present invention.

[0049] Figure 34 This is an axial aberration curve of the optical lens in Embodiment 6 of the present invention.

[0050] Figure 35 This is a chromatic aberration curve of the optical lens in Embodiment 6 of the present invention.

[0051] Figure 36 This is a relative illumination curve of the optical lens in Embodiment 6 of the present invention.

[0052] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0053] To better understand this application, various aspects of this application will be described in more detail with reference to the accompanying drawings. It should be understood that these detailed descriptions are merely illustrative of embodiments of this application and are not intended to limit the scope of this application in any way. Throughout the specification, the same reference numerals refer to the same elements. The expression "and / or" includes any and all combinations of one or more of the associated listed items.

[0054] It should be noted that in this specification, the terms "first," "second," "third," etc., are used only to distinguish one feature from another and do not imply any limitation on the features. Therefore, without departing from the teachings of the invention, the first lens discussed below may also be referred to as the second lens or the third lens.

[0055] In the accompanying drawings, the thickness, size, and shape of the lenses have been slightly exaggerated for ease of illustration. Specifically, the shapes of the spherical or aspherical surfaces shown in the drawings are illustrated by way of example. That is, the shapes of the spherical or aspherical surfaces are not limited to those shown in the drawings. The drawings are for illustrative purposes only and are not strictly to scale.

[0056] In this article, the paraxial region refers to the region near the optical axis. If the lens surface is convex and the location of the convexity is not defined, it means that the lens surface is convex at least in the paraxial region; if the lens surface is concave and the location of the concaveness is not defined, it means that the lens surface is concave at least in the paraxial region. The surface of each lens closest to the subject is called the object-side surface of the lens, and the surface of each lens closest to the imaging plane is called the image-side surface of the lens.

[0057] It should also be understood that the terms "comprising," "including," "having," "containing," and / or "comprising," when used in this specification, indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. Furthermore, when expressions such as "at least one of..." appear after a list of listed features, they modify the entire list of features, not individual elements in the list. Additionally, when describing embodiments of this application, the word "may" is used to mean "one or more embodiments of this application." And the term "exemplary" is intended to refer to an example or illustration.

[0058] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense unless expressly so specified herein.

[0059] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0060] The optical lens provided in this embodiment of the invention has five lenses with optical power, which are arranged sequentially from the object side to the imaging plane along the optical axis as a first lens, a second lens, a third lens, a fourth lens, and a fifth lens.

[0061] In some embodiments, the first lens may have negative optical power, with its object-side surface being concave and its image-side surface being either concave or convex. The second lens may have positive optical power, with its object-side surface being convex and its image-side surface being concave. The third lens may have negative optical power, with its object-side surface being either concave or convex and its image-side surface being concave. The fourth lens may have positive optical power, with its object-side surface being convex and its image-side surface being concave. The fifth lens may have positive optical power, with its object-side surface being convex and its image-side surface being either concave or convex.

[0062] In some embodiments, the optical lens may also include an aperture stop, which may be located between the second lens and the third lens. It is understood that the aperture stop is used to limit the amount of light entering the lens to change the brightness of the image. When the aperture stop is located between the second and third lenses, it facilitates the correction of aperture aberrations.

[0063] In some embodiments, the optical lens may further include a filter and a protective glass, which may be sequentially disposed between the fifth lens and the imaging surface along the optical axis. The filter is used to filter out interfering light and prevent it from reaching the imaging surface of the optical lens and affecting normal imaging. The protective glass plays a role in protecting the optical lens and preventing the photosensitive chip from being damaged and affecting the imaging effect of the lens.

[0064] In some embodiments, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 0.8 < f2 / f < 1.1; The radius of curvature R3 of the object side surface of the second lens and the effective focal length f of the optical lens satisfy: 0.6 < R3 / f < 0.95; the radius of curvature R4 of the image side surface of the second lens and the effective focal length f of the optical lens satisfy: 5.5 < R4 / f < 8.5. Meeting the above conditions, the second lens adopts a positive focal lens with a strong refractive power, which can converge the incident light at the front end, is beneficial to correcting the aberration and distortion of the edge field of view brought by the front lens group, makes the lens have a small distortion, and can provide a high-definition imaging effect. At the same time, reasonably controlling the relationship between the radius of curvature of the object side surface and the image side surface of the second lens and the effective focal length of the optical lens is beneficial to controlling the shape of the second lens, optimizing the aberration balance of the lens group, and improving the imaging quality.

[0065] In some embodiments, the combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: 0.65 < f12 / f < 1.3. Meeting the above requirements, by reasonably distributing the optical power from the first lens to the second lens, the deflection angle of the light at the front end of the lens is reduced, and the generation of various off-axis aberrations is reduced.

[0066] In some embodiments, the clear aperture semi-diameter d1 of the object side surface of the first lens and the clear aperture semi-diameter d10 of the image side surface of the fifth lens satisfy: 1.3 < d1 / d10 < 2.1. By reasonably setting the ratio of the apertures of the first and last lenses, the lens can have a smaller head size while having a larger imaging surface, and can better meet the balance of miniaturization and high pixel.

[0067] In some embodiments, the sagittal height SAG10 of the clear aperture semi-diameter of the image side surface of the fifth lens and the clear aperture semi-diameter d10 of the image side surface of the fifth lens satisfy: -0.1 < SAG10 / d10 < 0.1. Reasonably controlling the sagittal height and aperture of the image side surface of the fifth lens, controlling the light beam trend and performing final imaging, ensuring that the opening angle of the fifth lens is within a certain range, is beneficial to the optical lens to achieve high resolution and makes the optical lens have high imaging quality.

[0068] In some embodiments, the distance CT12 between the first lens and the second lens on the optical axis and the total optical length TTL of the optical lens satisfy: 0.22 < CT12 / TTL < 0.38. By reasonably controlling the air gap between the first lens and the second lens on the optical axis, the deflection trend of light between the first lens and the second lens can be slowed down, which is beneficial to achieving the balance of the long focal length and high pixel of the lens.

[0069] In some embodiments, the distance CT23 between the second lens and the third lens on the optical axis, the distance CT34 between the third lens and the fourth lens on the optical axis, the distance CT45 between the fourth lens and the fifth lens on the optical axis and the total optical length TTL of the optical lens satisfy: 0.025 < (CT23 + CT34 + CT45) / TTL < 0.04. Satisfying the above conditional formula, by reasonably controlling the proportion of the sum of the air gaps between the second lens, the third lens, the fourth lens and the fifth lens in the total optical length, it is beneficial to make the distribution of each lens more compact, beneficial to shortening the total length of the optical lens, and achieving the miniaturization of the lens.

[0070] In some embodiments, the sagittal height SAG3 of the clear aperture semi-diameter on the object side of the second lens, the sagittal height SAG4 of the clear aperture semi-diameter on the image side of the second lens and the central thickness CT2 of the second lens satisfy: -0.5 < (SAG4 - SAG3) / CT2 < -0.27. Satisfying the above conditions can limit the degree of central depression of the second lens and reduce the difficulty of aberration correction in the marginal field of view.

[0071] In some embodiments, the total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.8 < TTL / f < 4. It can effectively limit the length of the lens, which is beneficial to achieving the miniaturization of the optical lens.

[0072] In some embodiments, the clear aperture semi-diameter d1 on the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.8 < d1 / IH / tan(FOV / 2) < 1.1. Satisfying the above range can ensure the balance between the size of the optical lens, the field angle and the image plane.

[0073] In some embodiments, the focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < f5 / f < 1.8; the radius of curvature R9 of the object side of the fifth lens and the radius of curvature R10 of the image side of the fifth lens satisfy: -2 < (R9 - R10) / (R9 + R10) < -0.5. The fifth lens performs the final imaging on the light beam converged by the fourth lens. Ensuring that the effective focal length of the fifth lens is within a certain range is beneficial to achieving high imaging quality. At the same time, it can make the fifth lens have appropriate optical power and surface shape, which is beneficial to balancing the astigmatism and field curvature of the optical lens and improving the imaging quality of the optical lens.

[0074] In some embodiments, the central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy: 2.5 < CT2 / CT3 < 5. This enables a reasonable configuration of the ratio of the thickness of the second lens on the optical axis to the thickness of the third lens on the optical axis. The second lens and the third lens can regulate each other, maintaining the characteristic of miniaturization of the optical system.

[0075] In some embodiments, the combined focal length f12 of the first lens and the second lens and the combined focal length f345 of the third lens, the fourth lens, and the fifth lens satisfy: -0.3 < f12 / f345 < 0.4. Meeting the above range can reasonably distribute the proportion of the optical power of the lens groups before and after the aperture, increase the relative illumination of the lens, and improve the imaging quality of the lens.

[0076] In some embodiments, the combined focal length f345 of the third lens, the fourth lens, and the fifth lens and the effective focal length f of the optical lens satisfy: -8 < f345 / f < 25. Meeting the above requirements, by reasonably distributing the optical power of the third lens to the fifth lens, the focal length of the optical lens is balanced, the correction ability of various aberrations at the rear end of the lens is improved, and the imaging quality of the optical lens is enhanced.

[0077] In some embodiments, the half clear aperture d1 of the object side surface of the first lens and the true image height IH corresponding to the maximum field angle of the optical lens satisfy: 0.55 < d1 / IH < 0.8. Meeting the above conditions can ensure that the lens has a large field angle while ensuring that the overall size of the lens is appropriate.

[0078] In some embodiments, the sagittal height SAG5 of the half clear aperture of the object side surface of the third lens, the sagittal height SAG6 of the half clear aperture of the image side surface of the third lens, and the central thickness CT3 of the third lens satisfy: 0.85 < (SAG6 - SAG5) / CT3 < 1.55. Meeting the above conditions, by controlling the relationship between the height difference of the sagittal heights of the image side surface and the object side surface of the third lens and the central thickness of the third lens, it is beneficial to correct the coma of the off-axis field, and it is beneficial to improve the imaging quality of the off-axis field of the optical lens.

[0079] In some embodiments, the sagittal height SAG7 of the half clear aperture of the object side surface of the fourth lens, the sagittal height SAG8 of the half clear aperture of the image side surface of the fourth lens, and the central thickness CT4 of the fourth lens satisfy: -0.36 < (SAG8 - SAG7) / CT4 < 0.28. Meeting the above conditions can control the surface shape of the object side surface of the fourth lens, which is beneficial to the manufacture and shaping of the fourth lens, reducing the defective rate. In addition, it can also prevent the surface shape from being too curved and complex, making the field curvature of the system tend to be balanced.

[0080] In some embodiments, the total optical length TTL of the optical lens and the true image height IH corresponding to the maximum field angle of view of the optical lens satisfy: 2.7 < TTL / IH < 3.7. This can better achieve the miniaturization of the lens, and at the same time ensure that the lens has a larger image plane under the same total length, and can match a larger-sized imaging chip to achieve high-definition imaging.

[0081] In some embodiments, the true image height IH corresponding to the maximum field angle of view of the optical lens, the effective focal length f of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.7 < (IH / 2) / (f × tan(FOV / 2)) < 0.85. Meeting the above requirements indicates that the optical distortion of the optical lens is well controlled, improving the resolution of the optical lens.

[0082] In some embodiments, the maximum field angle FOV of the optical lens and the aperture value Fno of the optical lens satisfy: 32° < FOV / Fno < 38°. Meeting the above conditions is beneficial to increasing the light input of the lens, enabling the lens to achieve high-definition imaging even in a dim environment.

[0083] In some embodiments, the true image height IH corresponding to the maximum field angle of view of the optical lens and the entrance pupil diameter EPD of the optical lens satisfy: 1.9 < IH / EPD < 2.3. Meeting the above range enables the optical lens to satisfy a large image plane while also ensuring sufficient image plane brightness in the peripheral field of view, preventing the occurrence of vignetting phenomena, thereby improving the imaging quality.

[0084] In some embodiments, the true image height IH corresponding to the maximum field angle of view of the optical lens and the effective focal length f of the optical lens satisfy: 0.95 < IH / f < 1.25. Meeting the above conditions can achieve a larger field angle of view and imaging range, and can achieve the characteristics of a large image plane while ensuring the depth of field of the optical lens, thereby improving the imaging quality of the optical system.

[0085] In some embodiments, the distance BL on the optical axis from the image side of the fifth lens to the imaging plane and the effective focal length f of the optical lens satisfy: 0.8 < BL / f < 1.25. Meeting the above range is beneficial to achieving a balance between obtaining good imaging quality and easy assembly, ensuring the imaging quality of the optical lens while avoiding interference between the lens and other components, and reducing the assembly process difficulty of the camera module.

[0086] In some embodiments, the total optical length TTL of the optical lens, the true image height IH corresponding to the maximum field angle of view of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 0.01 / ° < TTL / IH / FOV < 0.06 / °. Meeting the above range can achieve a balance among large image height, long focal length, and miniaturization, and improve the imaging quality of the optical lens.

[0087] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens, the effective focal length f of the optical lens, and the maximum field angle FOV of the optical lens satisfy: 60° < f × FOV / IH < 70°. By satisfying the above conditional formula, by reasonably restricting the relationship among the focal length, field angle, and image height of the optical lens, it is beneficial to achieve the balance between the field angle of the optical lens and large-target imaging, and better meet the usage requirements of high-image-quality shooting of the optical lens.

[0088] In some embodiments, the total optical length TTL of the optical lens and the sum ∑CT of the central thicknesses of the first lens to the fifth lens along the optical axis satisfy: 0.34 < ∑CT / TTL < 0.44. By satisfying the above range, the total length of the optical lens can be effectively compressed, and at the same time, it is beneficial to the structural design and production process of the optical lens.

[0089] In some embodiments, the distance BL on the optical axis from the image side of the fifth lens to the imaging surface and the total optical length TTL of the optical lens satisfy: 0.23 < BL / TTL < 0.35. This is beneficial to achieving a short back focal length of the optical lens. Under the condition of ensuring sufficient space for the installation and focusing of optical elements, it is beneficial to achieve the miniaturization of the optical lens.

[0090] In some embodiments, the true image height IH corresponding to the maximum field angle of the optical lens and the F-number Fno of the optical lens satisfy: 3 mm < IH / Fno < 3.5 mm. By satisfying the above conditions, while maintaining a large image plane for the optical lens, it is ensured that the optical lens has a large aperture, achieving the balance between a large image plane and a large aperture.

[0091] In some embodiments, the focal length f1 of the first lens and the effective focal length f of the optical lens satisfy: -3.5 < f1 / f < -1.7; the radius of curvature R1 of the object side of the first lens and the radius of curvature R2 of the image side of the first lens satisfy: -18 < (R1 - R2) / (R1 + R2) < 120. The first lens has an appropriate negative focal length, which is beneficial to expanding the field angle of the optical lens. At the same time, it is beneficial for light to diverge, obtaining a larger picture, effectively eliminating aberration, and improving the resolution ability of the optical lens.

[0092] In some embodiments, the focal length f3 of the third lens and the effective focal length f of the optical lens satisfy: -1 < f3 / f < -0.65. By satisfying the above conditions, the third lens uses a negative focal lens with strong refractive power, which is beneficial to further increasing the imaging area of the optical lens, and at the same time balancing various aberrations generated by the front group of lenses, and improving the imaging quality of the optical lens.

[0093] In some embodiments, the focal length f2 of the second lens and the focal length f3 of the third lens satisfy: -1.8 < f2 / f3 < -0.85. By reasonably setting the focal length ratio of the second lens and the third lens, the system length can be shortened, the aberration and the distortion of the marginal field of view can be reduced, so that the lens has less distortion and can provide a high-definition imaging effect.

[0094] In some embodiments, the focal length f3 of the third lens and the focal length f4 of the fourth lens satisfy: -0.6 < f3 / f4 < 0. Meeting the above conditions, by reasonably setting the focal lengths of the third and fourth lenses, the convergence of light can be better achieved, the distance for light to enter the next lens can be shortened, which is beneficial to the miniaturization of the optical lens.

[0095] In some embodiments, the central thickness CT3 of the third lens and the central thickness CT4 of the fourth lens satisfy: 0.31 < CT3 / CT4 < 0.88. Meeting the above relational expression and matching with each other help to eliminate axial chromatic aberration.

[0096] In some embodiments, the curvature radius R1 of the object side surface of the first lens and the effective focal length f of the optical lens satisfy: -2.2 < R1 / f < -1.4. By reasonably configuring the ratio of the curvature radius of the object side surface of the first lens to the effective focal length of the optical lens, the first lens can collect as much light with a large field angle as possible and make the light enter the rear system smoothly, increasing the light transmission amount of the optical lens and effectively expanding the field of view range of the optical lens.

[0097] In some embodiments, the curvature radius R7 of the object side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 0.55 < R7 / f < 0.8; the curvature radius R8 of the image side surface of the fourth lens and the effective focal length f of the optical lens satisfy: 0.6 < R8 / f < 22. Meeting the above ranges can make the fourth lens have an appropriate surface shape, which is beneficial to balancing the astigmatism and field curvature of the optical lens and improving the imaging quality of the optical lens.

[0098] In some embodiments, the curvature radius R3 of the object side surface of the second lens and the curvature radius R4 of the image side surface of the second lens satisfy: -0.9 < (R3 - R4) / (R3 + R4) < -0.7. By making the optical system satisfy the above relational expression, it is beneficial to reasonably configure the ratio of the curvature radius of the object side surface of the second lens to the curvature radius of the image side surface of the second lens, control the shape of the second lens, comprehensively balance the spherical aberration, chromatic aberration and field curvature of the optical system, reduce the risk of ghost imaging, improve the resolution ability of the optical system, and at the same time, it is also beneficial to reduce the processing difficulty of the second lens.

[0099] In some embodiments, the optical lens satisfies the following conditional expressions: 5.5 mm < f < 6.5 mm; 2.5 mm < EPD < 3.5 mm; 18 mm < TTL < 23 mm; 1.9 < Fno < 2.1; 18° < CRA < 23°; 5 mm < BL < 7 mm; 65° < FOV < 75°; 6 mm < IH < 7 mm. In the above conditional expressions, f represents the effective focal length of the optical lens, EPD represents the entrance pupil diameter of the optical lens, TTL represents the overall optical length of the optical lens, Fno represents the aperture value of the optical lens, CRA represents the chief ray angle of incidence at the maximum image height of the optical lens, BL represents the distance from the image side of the fifth lens to the imaging surface on the optical axis, FOV represents the maximum field angle of the optical lens, and IH represents the true image height corresponding to the maximum field angle of the optical lens. Meeting the above ranges, the optical lens has at least one or more advantages such as a large target surface, a large aperture, and a long focal length characteristic.

[0100] In some embodiments, the lens material of the optical lens provided by the present invention can be glass or plastic. When the lens material is plastic, the production cost can be effectively reduced. On the other hand, when the lens material is glass, the geometric chromatic aberration of the optical system can be effectively corrected through the low dispersion characteristic of the glass itself. The third lens and the fourth lens of the present invention are made of plastic material; the first lens, the second lens, and the fifth lens are made of glass material.

[0101] In some embodiments, the first lens, the second lens, the third lens, the fourth lens, and the fifth lens can adopt spherical lenses or aspherical lenses. Compared with the spherical structure, the aspherical structure can effectively reduce the aberration of the optical system, thereby reducing the number of lenses and the size of the lenses, and better realizing the miniaturization of the lens. More specifically, the third lens and the fourth lens of the present invention adopt aspherical lenses; the first lens, the second lens, and the fifth lens adopt spherical lenses.

[0102] In each embodiment of the present invention, when the lens adopts an aspherical lens, the shapes of the aspherical surfaces of the optical lens satisfy the following equations: ; where z is the distance between the surface and the vertex of the surface in the optical axis direction, h is the distance from the optical axis to the surface, c is the curvature of the vertex of the surface, K is the conic coefficient, and B, C, D, E, F, G, H are the fourth-order, sixth-order, eighth-order, tenth-order, twelfth-order, fourteenth-order, and sixteenth-order surface coefficients respectively.

[0103] The present invention will be further described below with reference to several embodiments. In each embodiment, the thickness, radius of curvature, and material selection of each lens in the optical lens are different; for specific differences, please refer to the parameter tables of each embodiment. The following embodiments are merely preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the following embodiments. Any changes, substitutions, combinations, or simplifications made without departing from the innovative points of the present invention should be considered equivalent substitutions and are included within the protection scope of the present invention.

[0104] Example 1 Please see Figure 1 The figure shown is a schematic diagram of the structure of the optical lens 100 provided in Embodiment 1 of the present invention. The optical lens 100 includes, in sequence along the optical axis from the object side to the imaging surface: a first lens L1, a second lens L2, an aperture ST, a third lens L3, a fourth lens L4, a fifth lens L5, a filter G1, and a protective glass G2.

[0105] Among them, the first lens L1 has negative optical power, its object side S1 is concave, and its image side S2 is convex. The second lens L2 has positive optical power, its object side S3 is convex, and its image side S4 is concave. The third lens L3 has negative optical power, its object side S5 is convex, and its image side S6 is concave. The fourth lens L4 has positive optical power, its object side S7 is convex, and its image side S8 is concave. The fifth lens L5 has positive optical power, its object side S9 is convex, and its image side S10 is convex. The object-side surface S11 and the image-side surface S12 of the filter G1 are both planar. The object side S13 and the image side S14 of the protective glass G2 are both flat. The imaging plane S15 is a plane.

[0106] The first lens L1, the second lens L2, and the fifth lens L5 are glass spherical lenses; the third lens L3 and the fourth lens L4 are plastic aspherical lenses.

[0107] The relevant parameters of each lens in the optical lens 100 in Example 1 are shown in Table 1-1.

[0108] Table 1-1 The surface profile parameters of the aspherical lens of the optical lens 100 in Example 1 are shown in Table 1-2.

[0109] Table 1-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 100 are respectively as follows: Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown.

[0110] Figure 2 The field curvature curve of Example 1 is shown, which represents the degree of curvature of light in the meridional and sagittal image planes. The horizontal axis represents the offset (unit: mm), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the field curvature of the meridional and sagittal image planes is controlled within -0.04 mm to 0.08 mm, indicating that the optical lens can effectively correct the field curvature.

[0111] Figure 3 The F-Theta distortion curve of Example 1 is shown, which represents the F-Theta distortion of light of different wavelengths at different image heights on the imaging plane. The horizontal axis represents the distortion value (unit: %), and the vertical axis represents the half field of view (unit: °). As can be seen from the figure, the F-Theta distortion of the optical lens is controlled within -15% to 0, indicating that the optical lens can correct distortion well.

[0112] Figure 4 The diagram shows the axial aberration curves for Example 1, representing the aberrations of each wavelength along the optical axis at the imaging plane. The horizontal axis represents the axial aberration value (unit: mm), and the vertical axis represents the normalized pupil radius. As can be seen from the diagram, the axial aberration offset is controlled within ±0.03 mm, indicating that the optical lens can effectively correct axial aberrations.

[0113] Figure 5 The diagram shows the transverse chromatic aberration curves for Example 1, representing the chromatic aberration of each wavelength relative to the center wavelength (0.558 μm) at different image heights on the imaging plane. The horizontal axis represents the transverse chromatic aberration value of each wavelength relative to the center wavelength (unit: μm), and the vertical axis represents the normalized field of view. As can be seen from the diagram, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2 μm, indicating that the optical lens can effectively correct chromatic aberration.

[0114] Figure 6 The relative illumination curve of Example 1 is shown, which represents the relative illumination value at different field-of-view angles on the imaging plane. The horizontal axis represents the half-field angle (unit: °), and the vertical axis represents the relative illumination (unit: %). As can be seen from the figure, the relative illumination value of the optical lens is greater than 80%, indicating that the optical lens has good relative illumination.

[0115] Example 2 Please see Figure 7The figure shows a schematic diagram of the structure of the optical lens 200 provided in Embodiment 2 of the present invention. The main difference between this embodiment and Embodiment 1 is that the image side S1 of the first lens L1 is concave; the object side S5 of the third lens L3 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0116] The relevant parameters of each lens in the optical lens 200 in Example 2 are shown in Table 2-1.

[0117] Table 2-1 The surface profile parameters of the aspherical lens of the optical lens 200 in Example 2 are shown in Table 2-2.

[0118] Table 2-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 200 are respectively as follows: Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown.

[0119] from Figure 8 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.04mm, indicating that the optical lens can effectively correct the field curvature.

[0120] from Figure 9 As can be seen, the F-Theta distortion of the optical lens is controlled within -15% to 0, indicating that the optical lens can correct distortion well.

[0121] from Figure 10 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.03mm, indicating that the optical lens can effectively correct axial aberration.

[0122] from Figure 11 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens can effectively correct chromatic aberration.

[0123] from Figure 12 As can be seen, the relative illumination value of the optical lens is greater than 90%, indicating that the optical lens has good relative illumination.

[0124] Example 3 Please see Figure 13The figure shows a schematic diagram of the structure of the optical lens 300 provided in Embodiment 3 of the present invention. The main difference between this embodiment and Embodiment 1 is that: the image-side surface S1 of the first lens L1 is concave; the object-side surface S5 of the third lens L3 is concave; the image-side surface S10 of the fifth lens L5 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0125] The relevant parameters of each lens in the optical lens 300 in Example 3 are shown in Table 3-1.

[0126] Table 3-1 The surface profile parameters of the aspherical lens of the optical lens 300 in Example 3 are shown in Table 3-2.

[0127] Table 3-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 300 are respectively as follows: Figure 14 , Figure 15 , Figure 16 , Figure 17 , Figure 18 As shown.

[0128] from Figure 14 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within -0.02mm to 0.06mm, indicating that the optical lens can effectively correct the field curvature.

[0129] from Figure 15 As can be seen, the F-Theta distortion of the optical lens is controlled within -15% to 0, indicating that the optical lens can correct distortion well.

[0130] from Figure 16 As can be seen, the axial aberration offset is controlled within -0.02mm to 0.05mm, indicating that the optical lens can effectively correct axial aberration.

[0131] from Figure 17 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens can effectively correct chromatic aberration.

[0132] from Figure 18 As can be seen, the relative illumination value of the optical lens is greater than 90%, indicating that the optical lens has good relative illumination.

[0133] Example 4 Please see Figure 19The figure shows a schematic diagram of the structure of the optical lens 400 provided in Embodiment 4 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S5 of the third lens L3 is concave; the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0134] The relevant parameters of each lens in the optical lens 400 in Example 4 are shown in Table 4-1.

[0135] Table 4-1 The surface profile parameters of the aspherical lens of the optical lens 400 in Example 4 are shown in Table 4-2.

[0136] Table 4-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 400 are respectively as follows: Figure 20 , Figure 21 , Figure 22 , Figure 23 , Figure 24 As shown.

[0137] from Figure 20 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within 0~0.08mm, indicating that the optical lens can effectively correct the field curvature.

[0138] from Figure 21 As can be seen, the F-Theta distortion of the optical lens is controlled within -15% to 0, indicating that the optical lens can correct distortion well.

[0139] from Figure 22 As can be seen, the axial aberration offset is controlled within ±0.04mm, indicating that the optical lens can effectively correct axial aberration.

[0140] from Figure 23 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens can effectively correct chromatic aberration.

[0141] from Figure 24 As can be seen, the relative illumination value of the optical lens is greater than 80%, indicating that the optical lens has good relative illumination.

[0142] Example 5 Please see Figure 25The figure shows a schematic diagram of the structure of the optical lens 500 provided in Embodiment 5 of the present invention. The main difference between this embodiment and Embodiment 1 is that the object side surface S5 of the third lens L3 is concave; the image side surface S10 of the fifth lens L5 is concave; and the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0143] The relevant parameters of each lens in the optical lens 500 in Example 5 are shown in Table 5-1.

[0144] Table 5-1 The surface profile parameters of the aspherical lens of the optical lens 500 in Example 5 are shown in Table 5-2.

[0145] Table 5-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 500 are respectively as follows: Figure 26 , Figure 27 , Figure 28 , Figure 29 , Figure 30 As shown.

[0146] from Figure 26 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.04mm, indicating that the optical lens can effectively correct the field curvature.

[0147] from Figure 27 As can be seen, the F-Theta distortion of the optical lens is controlled within -15% to 0, indicating that the optical lens can correct distortion well.

[0148] from Figure 28 As can be seen, the axial aberration offset is controlled within -0.01mm to 0.03mm, indicating that the optical lens can effectively correct axial aberration.

[0149] from Figure 29 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens can effectively correct chromatic aberration.

[0150] from Figure 30 As can be seen, the relative illumination value of the optical lens is greater than 85%, indicating that the optical lens has good relative illumination.

[0151] Example 6 Please see Figure 31The figure shown is a schematic diagram of the structure of the optical lens 600 provided in Embodiment 6 of the present invention. The main difference between this embodiment and Embodiment 1 is that the optical parameters such as the radius of curvature and lens thickness of each lens surface are different.

[0152] The relevant parameters of each lens in the optical lens 600 in Example 6 are shown in Table 6-1.

[0153] Table 6-1 The surface profile parameters of the aspherical lens of the optical lens 600 in Example 6 are shown in Table 6-2.

[0154] Table 6-2 In this embodiment, the field curvature curve, F-Theta distortion curve, axial aberration curve, transverse chromatic aberration curve, and relative illumination curve of the optical lens 600 are respectively as follows: Figure 32 , Figure 33 , Figure 34 , Figure 35 , Figure 36 As shown.

[0155] from Figure 32 As can be seen, the field curvature of the meridional and sagittal image planes is controlled within ±0.05mm, indicating that the optical lens can effectively correct the field curvature.

[0156] from Figure 33 As can be seen, the F-Theta distortion of the optical lens is controlled within -15% to 0, indicating that the optical lens can correct distortion well.

[0157] from Figure 34 As can be seen, the axial aberration offset is controlled within ±0.05mm, indicating that the optical lens can effectively correct axial aberration.

[0158] from Figure 35 As can be seen, the transverse chromatic aberration of the longest and shortest wavelengths is controlled within ±2μm, indicating that the optical lens can effectively correct chromatic aberration.

[0159] from Figure 36 As can be seen, the relative illumination value of the optical lens is greater than 80%, indicating that the optical lens has good relative illumination.

[0160] Please refer to Table 7 for the optical characteristics corresponding to each of the above embodiments, including the effective focal length f, total optical length TTL, aperture value Fno, true image height IH corresponding to the maximum field of view, maximum field of view FOV, principal ray incident angle CRA at the maximum image height, distance BL from the image side of the fifth lens to the imaging plane on the optical axis, and the numerical values ​​corresponding to each conditional expression in each embodiment.

[0161] Table 7 In summary, the optical lens provided by the present invention employs five lenses with specific optical power. Through specific surface shape matching and reasonable optical power distribution, it can improve the imaging quality of the optical lens, reduce aberrations, and enhance the imaging quality of the optical lens, giving the lens one or more advantages such as large image area, long focal length, large aperture, and high imaging quality.

[0162] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0163] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. An optical lens comprising five lenses having optical power, characterized in that, It sequentially includes from the object side to the imaging surface along the optical axis: A first lens with a negative optical power, whose object side is concave; A second lens with a positive optical power, whose object side is convex and whose image side is concave; A third lens with a negative optical power, whose image side is concave; A fourth lens with a positive optical power, whose object side is convex and whose image side is concave; A fifth lens with a positive optical power, whose object side is convex; Wherein, the focal length f2 of the second lens and the effective focal length f of the optical lens satisfy: 0.8 < f2 / f < 1.1; the curvature radius R3 of the object side of the second lens and the effective focal length f of the optical lens satisfy: 0.6 < R3 / f < 0.95; the curvature radius R4 of the image side of the second lens and the effective focal length f of the optical lens satisfy: 5.5 < R4 / f < 8.

5.

2. The optical lens according to claim 1, characterized in that, The combined focal length f12 of the first lens and the second lens and the effective focal length f of the optical lens satisfy: 0.65 < f12 / f < 1.

3.

3. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter d1 of the object side of the first lens and the clear aperture semi-diameter d10 of the image side of the fifth lens satisfy: 1.3 < d1 / d10 < 2.

1.

4. The optical lens according to claim 1, characterized in that, The sagittal height SAG10 of the clear aperture semi-diameter of the image side of the fifth lens and the clear aperture semi-diameter d10 of the image side of the fifth lens satisfy: -0.1 < SAG10 / d10 < 0.

1.

5. The optical lens according to claim 1, characterized in that, The spacing CT12 of the first lens and the second lens on the optical axis and the total optical length TTL of the optical lens satisfy: 0.22 < CT12 / TTL < 0.38; the spacing CT23 of the second lens and the third lens on the optical axis, the spacing CT34 of the third lens and the fourth lens on the optical axis, and the spacing CT45 of the fourth lens and the fifth lens on the optical axis and the total optical length TTL of the optical lens satisfy: 0.025 < (CT23 + CT34 + CT45) / TTL < 0.

04.

6. The optical lens according to claim 1, characterized in that, The sagittal height SAG3 of the clear aperture semi-diameter of the object side of the second lens, the sagittal height SAG4 of the clear aperture semi-diameter of the image side of the second lens and the central thickness CT2 of the second lens satisfy: -0.5 < (SAG4 - SAG3) / CT2 < -0.

27.

7. The optical lens according to claim 1, characterized in that, The total optical length TTL of the optical lens and the effective focal length f of the optical lens satisfy: 2.8 < TTL / f < 4.

8. The optical lens according to claim 1, characterized in that, The clear aperture semi-diameter d1 of the object side of the first lens, the true image height IH corresponding to the maximum field angle of the optical lens and the maximum field angle FOV of the optical lens satisfy: 0.8 < d1 / IH / tan(FOV / 2) < 1.

1.

9. The optical lens according to claim 1, characterized in that, The focal length f5 of the fifth lens and the effective focal length f of the optical lens satisfy: 1 < f5 / f < 1.

8.

10. The optical lens according to claim 1, characterized in that, The central thickness CT2 of the second lens and the central thickness CT3 of the third lens satisfy: 2.5 < CT2 / CT3 < 5.

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